Abstract: Organic matter of most Middle-Upper Proterozoic hydrocarbon sources in northern China has highly evolved to high-maturity or over-maturity stage(Condensate-wet-Methane zone).Shale and lime-shale samples of lower or median maturity(Rb=0.38～0.6％)were selected from the Upper Proterozoic Xiamaling Formation at Xiahuayuan,Zhangjiakou.Simu1ation experiments have been pertormed to study the thermal evolution of the Middle-Upper Proterozoic hydrocarbon sources and to establish a generation mode1.Simulation experiments indicate that simulate temperature of the low-maturity stage is below 275℃ (quite R0 <0.8％),the maturity stage between 275-350℃ (quite R0 0.8～1.32％),High-maturity stage between 350～410℃ (quite R0 1.32-2.0％),and over-maturity stage exceeding 410℃ (quite R0 >2.0％). The higher the simulation temperature,the heavier the carbon isotope( δ13C) of the outcoming hydrocarbon,indicating an effect of temperature on δ13C. Dissolvable aroma-hydrocarbons tend to aggregate at the over-maturity stage,resulting in the reduction of aroma-hydrocarbons and the increase of bitumen.Many characteristics of dissolvable organic matter are reversed at high-maturity and over-maturity stages,such as the appearance of double peaks of normal paraffins, and the predominance of odd-carbon over dual-carbon hydrocarbons.Once Rb exceeds 0.8 1％ as temperature rises,bitumen,litumen neflectance(Rb)will persist to the greater than the vitrinite reflectance at the same temperatures .Compared with water-free runs,water-present experiments will produce liguid hydrocarbons in higher quantities and with more heavy components,indicating that pyrolysis tooks place more intensely during water-free experiments and conditions of water-present runs corresponds better than natusal environments.